PURPOSE To describe a novel excimer laser ablation algorithm, termed optimized prolate ablation (OPA), that uses both topography and ocular aberrometry and maintains or improves the natural corneal shape postoperatively. METHODS A descriptive article outlining the theory behind this OPA algorithm. RESULTS The theoretical changes to the ablation algorithm described in this article will produ...

In spite of their low concentrations in soil solutions, low–molecular weight organic substances (LMWOS) such as amino acids, sugars, and uronic acids play a major role in the cycles of C and N in soil. With respect to their low concentrations and to possible matrix interferences, their analysis in soil leachates is a challenging task. We established two HPLC (high-performance liquid chromatogra...

A rapid, sensitive and reproducible HPLC method was developed and validated for the analysis of memantine in human plasma after derivatization with o-phthaldialdehyde (OPA) and fluorescence detection. Amantadine was used as internal standard. The derivatized memantine and amantadine were eluted in less than 10 min with no interference from endogenous plasma peaks. The analysis was carried out o...

Hydroxyl radical-induced oxidation of proteins and peptides can lead to the cleavage of the peptide, leading to a release of fragments. Here, we used high-performance liquid chromatography tandem mass spectrometry (HPLC-MS/MS) and pre-column online ortho-phthalaldehyde (OPA) derivatization-based amino acid analysis by HPLC with diode array detection and fluorescence detection to identify and qu...

A total number of 210 strains of lactobacilli were isolated from different sources – homemade yoghurts and cheeses, plants and human fecal samples. The species affiliation of the strains was analyzed by Amplified Ribosomal DNA Restriction Analysis (ARDRA) followed by 16S rDNA sequencing. The strain differentiation was obtained by methods of Pulsed Field Gel Electrophoresis (PFGE) and Amplified ...

The aim of the present work was to study the changes of the content of biogenic amines during winemaking and maturation processes of wines made from Vitis vinifera cv Sauvignon grapes from Slavonia region (vintage 2008). Biogenic amines were quantified using a reversed-phase high performance liquid chromatography (HPLC) with fluorescence detection after precolumn derivatization with o-phthalald...

We explored the possibility that circulating glutamine affects gamma-aminobutyric acid (GABA) levels in rat striatal tissue and GABA concentrations in striatal extracellular fluid (ECF). Striatal microdialysates, each collected over a 20 min interval, were obtained after no treatment, oral L-glutamine (0.5 g/kg), or glutamine followed by NMDA (administered via the microdialysis probe). GABA con...

Temporal relationship between viral and bacterial infections has been observed, and may arise via the action of virus-induced inflammatory cytokines. These, by upregulating epithelial receptors targeted by bacteria, may encourage greater bacterial infiltration. In this study, human epithelial cells exposed to interferon-gamma but not tumour necrosis factor-alpha or interleukin 1-beta supported ...

PURPOSE This study compared the measurements of intraocular pressure (IOP) and ocular pulse amplitude (OPA) using the Dynamic Contour Tonometry (DCT) over silicone hydrogel contact lenses of different modulus. Corneal biomechanics were also measured using the Ocular Response Analyzer (ORA). METHODS Forty-seven young (mean age 22.3 years, standard deviation 1.2 years) subjects had IOP, OPA, co...